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Comparing ray/src/rt/normal.c (file contents):
Revision 2.7 by greg, Wed Jan 15 11:41:44 1992 UTC vs.
Revision 2.27 by greg, Wed Jan 12 16:46:45 1994 UTC

#	Line 23 | Line 23 | static char SCCSid[] = "$SunId$ LBL";
23		extern double  specthresh;              /* specular sampling threshold */
24		extern double  specjitter;              /* specular sampling jitter */
25
26	+	static  gaussamp();
27	+
28		/*
29	<	*      This routine uses portions of the reflection
30	<	*  model described by Cook and Torrance.
29	<	*      The computation of specular components has been simplified by
30	<	*  numerous approximations and ommisions to improve speed.
29	>	*      This routine implements the isotropic Gaussian
30	>	*  model described by Ward in Siggraph `92 article.
31		*      We orient the surface towards the incoming ray, so a single
32		*  surface can be used to represent an infinitely thin object.
33		*
#	Line 38 | Line 38 | extern double  specjitter;             /* specular sampling jitte
38		*      red     grn     blu     rspec   rough   trans   tspec
39		*/
40
41	–	#define  BSPEC(m)       (6.0)           /* specularity parameter b */
42	–
41		/* specularity flags */
42		#define  SP_REFL        01              /* has reflected specular component */
43		#define  SP_TRAN        02              /* has transmitted specular */
44	<	#define  SP_PURE        010             /* purely specular (zero roughness) */
45	<	#define  SP_FLAT        020             /* flat reflecting surface */
46	<	#define  SP_RBLT        040             /* reflection below sample threshold */
47	<	#define  SP_TBLT        0100            /* transmission below threshold */
44	>	#define  SP_PURE        04              /* purely specular (zero roughness) */
45	>	#define  SP_FLAT        010             /* flat reflecting surface */
46	>	#define  SP_RBLT        020             /* reflection below sample threshold */
47	>	#define  SP_TBLT        040             /* transmission below threshold */
48
49		typedef struct {
50		OBJREC  *mp;            /* material pointer */
51	+	RAY  *rp;               /* ray pointer */
52		short  specfl;          /* specularity flags, defined above */
53		COLOR  mcolor;          /* color of this material */
54		COLOR  scolor;          /* color of specular component */
#	Line 71 | Line 70 | FVECT  ldir;                   /* light source direction */
70		double  omega;                  /* light source size */
71		{
72		double  ldot;
73	<	double  dtmp;
74	<	int     i;
73	>	double  dtmp, d2;
74	>	FVECT  vtmp;
75		COLOR  ctmp;
76
77		setcolor(cval, 0.0, 0.0, 0.0);
#	Line 99 | Line 98 | double  omega;                 /* light source size */
98		*  gaussian distribution model.
99		*/
100		/* roughness */
101	<	dtmp = 2.0*np->alpha2;
101	>	dtmp = np->alpha2;
102		/* + source if flat */
103		if (np->specfl & SP_FLAT)
104	<	dtmp += omega/(2.0*PI);
104	>	dtmp += omega/(4.0*PI);
105	>	/* half vector */
106	>	vtmp[0] = ldir[0] - np->rp->rdir[0];
107	>	vtmp[1] = ldir[1] - np->rp->rdir[1];
108	>	vtmp[2] = ldir[2] - np->rp->rdir[2];
109	>	d2 = DOT(vtmp, np->pnorm);
110	>	d2 *= d2;
111	>	d2 = (DOT(vtmp,vtmp) - d2) / d2;
112		/* gaussian */
113	<	dtmp = exp((DOT(np->vrefl,ldir)-1.)/dtmp)/(2.*PI)/dtmp;
113	>	dtmp = exp(-d2/dtmp)/(4.*PI*dtmp);
114		/* worth using? */
115		if (dtmp > FTINY) {
116		copycolor(ctmp, np->scolor);
117	<	dtmp *= omega / np->pdot;
117	>	dtmp *= omega * sqrt(ldot/np->pdot);
118		scalecolor(ctmp, dtmp);
119		addcolor(cval, ctmp);
120		}
#	Line 128 | Line 134 | double  omega;                 /* light source size */
134		*  is always modified by material color.
135		*/
136		/* roughness + source */
137	<	dtmp = np->alpha2 + omega/(2.0*PI);
137	>	dtmp = np->alpha2 + omega/PI;
138		/* gaussian */
139	<	dtmp = exp((DOT(np->prdir,ldir)-1.)/dtmp)/(2.*PI)/dtmp;
139	>	dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp);
140		/* worth using? */
141		if (dtmp > FTINY) {
142		copycolor(ctmp, np->mcolor);
143	<	dtmp *= np->tspec * omega / np->pdot;
143	>	dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot);
144		scalecolor(ctmp, dtmp);
145		addcolor(cval, ctmp);
146		}
#	Line 148 | Line 154 | register RAY  *r;
154		{
155		NORMDAT  nd;
156		double  transtest, transdist;
151	–	double  dtmp;
157		COLOR  ctmp;
158		register int  i;
159		/* easy shadow test */
160		if (r->crtype & SHADOW && m->otype != MAT_TRANS)
161	<	return;
161	>	return(1);
162
163		if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5))
164		objerror(m, USER, "bad number of arguments");
165		nd.mp = m;
166	+	nd.rp = r;
167		/* get material color */
168		setcolor(nd.mcolor, m->oargs.farg[0],
169		m->oargs.farg[1],
#	Line 177 | Line 183 | register RAY  *r;
183		nd.pdot = .001;                 /* non-zero for dirnorm() */
184		multcolor(nd.mcolor, r->pcol);          /* modify material color */
185		transtest = 0;
186	+	transdist = r->rot;
187		/* get specular component */
188		if ((nd.rspec = m->oargs.farg[3]) > FTINY) {
189		nd.specfl |= SP_REFL;
#	Line 186 | Line 193 | register RAY  *r;
193		else
194		setcolor(nd.scolor, 1.0, 1.0, 1.0);
195		scalecolor(nd.scolor, nd.rspec);
189	–	/* improved model */
190	–	dtmp = exp(-BSPEC(m)*nd.pdot);
191	–	for (i = 0; i < 3; i++)
192	–	colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp;
193	–	nd.rspec += (1.0-nd.rspec)*dtmp;
196		/* check threshold */
197	<	if (specthresh > FTINY &&
196	<	((specthresh >= 1.-FTINY ||
197	<	specthresh + (.1 - .2*urand(8199+samplendx))
198	<	> nd.rspec)))
197	>	if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY)
198		nd.specfl |= SP_RBLT;
199		/* compute reflected ray */
200		for (i = 0; i < 3; i++)
#	Line 222 | Line 221 | register RAY  *r;
221		if (nd.tspec > FTINY) {
222		nd.specfl |= SP_TRAN;
223		/* check threshold */
224	<	if (specthresh > FTINY &&
225	<	((specthresh >= 1.-FTINY ||
227	<	specthresh +
228	<	(.1 - .2*urand(7241+samplendx))
229	<	> nd.tspec)))
224	>	if (!(nd.specfl & SP_PURE) &&
225	>	specthresh >= nd.tspec-FTINY)
226		nd.specfl |= SP_TBLT;
227		if (r->crtype & SHADOW ||
228		DOT(r->pert,r->pert) <= FTINY*FTINY) {
#	Line 234 | Line 230 | register RAY  *r;
230		transtest = 2;
231		} else {
232		for (i = 0; i < 3; i++)         /* perturb */
233	<	nd.prdir[i] = r->rdir[i] -
238	<	.75*r->pert[i];
233	>	nd.prdir[i] = r->rdir[i] - r->pert[i];
234		if (DOT(nd.prdir, r->ron) < -FTINY)
235		normalize(nd.prdir);    /* OK */
236		else
#	Line 256 | Line 251 | register RAY  *r;
251		transtest *= bright(lr.rcol);
252		transdist = r->rot + lr.rt;
253		}
254	<	}
254	>	} else
255	>	transtest = 0;
256
257		if (r->crtype & SHADOW)                 /* the rest is shadow */
258	<	return;
258	>	return(1);
259		/* diffuse reflection */
260		nd.rdiff = 1.0 - nd.trans - nd.rspec;
261
262		if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY)
263	<	return;                         /* 100% pure specular */
263	>	return(1);                      /* 100% pure specular */
264
265	<	if (r->ro->otype == OBJ_FACE || r->ro->otype == OBJ_RING)
265	>	if (r->ro != NULL && (r->ro->otype == OBJ_FACE ||
266	>	r->ro->otype == OBJ_RING))
267		nd.specfl |= SP_FLAT;
268
269		if (nd.specfl & (SP_REFL|SP_TRAN) && !(nd.specfl & SP_PURE))
#	Line 297 | Line 294 | register RAY  *r;
294		/* check distance */
295		if (transtest > bright(r->rcol))
296		r->rt = transdist;
297	+
298	+	return(1);
299		}
300
301
#	Line 310 | Line 309 | register NORMDAT  *np;
309		double  rv[2];
310		double  d, sinp, cosp;
311		register int  i;
312	+	/* quick test */
313	+	if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL &&
314	+	(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN)
315	+	return;
316		/* set up sample coordinates */
317		v[0] = v[1] = v[2] = 0.0;
318		for (i = 0; i < 3; i++)
#	Line 346 | Line 349 | register NORMDAT  *np;
349		ndims--;
350		}
351		/* compute transmission */
352	+	if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN &&
353	+	rayorigin(&sr, r, SPECULAR, np->tspec) == 0) {
354	+	dimlist[ndims++] = (int)np->mp;
355	+	d = urand(ilhash(dimlist,ndims)+1823+samplendx);
356	+	multisamp(rv, 2, d);
357	+	d = 2.0*PI * rv[0];
358	+	cosp = cos(d);
359	+	sinp = sin(d);
360	+	rv[1] = 1.0 - specjitter*rv[1];
361	+	if (rv[1] <= FTINY)
362	+	d = 1.0;
363	+	else
364	+	d = sqrt( -log(rv[1]) * np->alpha2 );
365	+	for (i = 0; i < 3; i++)
366	+	sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]);
367	+	if (DOT(sr.rdir, r->ron) < -FTINY)
368	+	normalize(sr.rdir);             /* OK, normalize */
369	+	else
370	+	VCOPY(sr.rdir, np->prdir);      /* else no jitter */
371	+	rayvalue(&sr);
372	+	scalecolor(sr.rcol, np->tspec);
373	+	multcolor(sr.rcol, np->mcolor);         /* modified by color */
374	+	addcolor(r->rcol, sr.rcol);
375	+	ndims--;
376	+	}
377		}

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